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triangle

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noun tri·an·gle \ˈtrī-ˌaŋ-gəl\

Simple Definition of triangle

  • : a shape that is made up of three lines and three angles

  • : something that is shaped like a triangle

  • : a musical instrument that is made of a steel rod bent into the shape of a triangle and that you play by hitting with a metal rod

Source: Merriam-Webster's Learner's Dictionary

Full Definition of triangle

  1. 1 :  a polygon having three sides — compare spherical triangle

  2. 2a :  a percussion instrument consisting of a rod of steel bent into the form of a triangle open at one angle and sounded by striking with a small metal rodb :  a drafting instrument consisting of a thin flat right-angled triangle of wood or plastic with acute angles of 45 degrees or of 30 degrees and 60 degrees

  3. 3 :  a situation in which one member of a couple is involved in a love affair with a third person

Examples of triangle in a sentence

  1. She cut the sandwiches into triangles.



Illustration of triangle

Origin of triangle

Middle English, from Anglo-French, from Latin triangulum, from neuter of triangulus triangular, from tri- + angulus angle


First Known Use: 14th century



TRIANGLE Defined for Kids

triangle

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noun tri·an·gle \ˈtrī-ˌaŋ-gəl\

Definition of triangle for Students

  1. 1 :  a flat geometric figure that has three sides and three angles

  2. 2 :  something that has three sides and three angles <a triangle of land>

  3. 3 :  a musical instrument made of a steel rod bent in the shape of a triangle with one open angle




Medical Dictionary

triangle

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noun tri·an·gle \ˈtrī-ˌaŋ-gəl\

Medical Definition of triangle

  1. :  a three-sided region or space and especially an anatomical one—see anterior triangle, carotid triangle, femoral triangle, posterior triangle, suboccipital triangle





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